2011 INFINITI QX56 wiring diagram

ST-24
< SYMPTOM DIAGNOSIS >
HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
5. Check continuity between heated steering wheel relay harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK HEATED STEERING WHEEL RELAY
Check heated steering wheel relay. Refer to ST-19, "
Component Inspection (Heated Steering Wheel Relay)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace heated steering wheel relay. Refer to ST-7, "
Component Parts Location (Heated Steering
Wheel)".
6.DETECT MALFUNCTIONING ITEM
Check the following.
Battery
 Harness for short or open between bat tery and IPDM E/R. Refer to PG-11, "
Wiring Diagram - BATTERY
POWER SUPPLY -".
 10A fuse (No.76, located in the IPDM E/R). Refer to PG-143, "
Fuse, Connector and Terminal Arrangement".
 IPDM E/R
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
7.CHECK GROUND CIRCUIT
Check continuity between heated steering wheel switch harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace damaged parts.
8.CHECK HARNESS BETWEEN HEATED STEERING WHEEL RELAY AND HEATED STEERING WHEEL
SWITCH
1. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel switch harness connector terminal.
2. Check continuity between heated steering w heel relay harness connector terminal and ground.
Heated steering wheel relay Heated steering wheel
Continuity
Connector Terminal Connector Terminal
E90 5 M303 1 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 5 Not existed
Heated steering wheel switch GroundContinuity
Connector Terminal
M52 6 Existed
Heated steering wheel relay Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
E90 2 M52 2 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 2 Not existed
Revision: 2010 May2011 QX56

HEATED STEERING WHEEL SYSTEM DOES NOT ACTIVATE
ST-25
< SYMPTOM DIAGNOSIS >
C
D E
F
H I
J
K L
M A
B
ST
N
O P
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair or replace damaged parts.
9.CHECK HARNESS BETWEEN FUSE BLOCK (J/B) AND HEATED STEERING WHEEL SWITCH
1. Check continuity between fuse block (J/B) connec tor terminal and heated steering wheel switch harness
connector terminal.
2. Check continuity between fuse block (J/B) harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Repair or replace damaged parts.
10.DETECT MALFUNCTIONING ITEM
Check the following.
 Ignition switch
 Harness for short or open between ignition s witch and fuse block (J/B). Refer to PG-11, "
Wiring Diagram -
BATTERY POWER SUPPLY -".
 10A fuse [No.3, located in the fuse block (J/B)]. Refer to PG-143, "
Fuse, Connector and Terminal Arrange-
ment".
 Fuse block (J/B)
Is the inspection result normal?
YES >> Replace heated steering wheel switch. Refer to ST-56, "Removal and Installation".
NO >> Repair or replace damaged parts.
Fuse block (J/B) Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
M1 2A M52 1 Existed
Fuse block (J/B) GroundContinuity
Connector Terminal
M1 2A Not existed
Revision: 2010 May2011 QX56

HEATED STEERING WHEEL SWITCH INDICATOR LAMP DOES NOT TURN ON
ST-27
< SYMPTOM DIAGNOSIS >
C
D E
F
H I
J
K L
M A
B
ST
N
O P
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK HEATED STEERING WHEEL RELAY
Check heated steering wheel relay. Refer to ST-22, "
Component Inspection (Heated Steering Wheel Relay)".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace heated steering wheel relay. Refer to ST-7, "
Component Parts Location (Heated Steering
Wheel)".
5.CHECK HARNESS BETWEEN HEATED STEERING WHEEL RELAY AND HEATED STEERING WHEEL
SWITCH
1. Check continuity between heated steering wheel relay harness connector terminal and heated steering
wheel switch harness connector terminal.
2. Check continuity between heated steering w heel relay harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
6.CHECK HARNESS BETWEEN FUSE BLOCK (J/B) AND HEATED STEERING WHEEL SWITCH
1. Check continuity between fuse block (J/B) connec tor terminal and heated steering wheel switch harness
connector terminal.
2. Check continuity between fuse block (J/B) harness connector terminal and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace damaged parts.
7.DETECT MALFUNCTIONING ITEM
Check the following.
 Ignition switch
 Harness for short or open between ignition s witch and fuse block (J/B). Refer to PG-11, "
Wiring Diagram -
BATTERY POWER SUPPLY -".
 10A fuse [No.3, located in the fuse block (J/B)]. Refer to PG-143, "
Fuse, Connector and Terminal Arrange-
ment".
 Fuse block (J/B)
Is the inspection result normal?
YES >> Replace heated steering wheel switch. Refer to ST-56, "Removal and Installation".
Heated steering wheel relay Heated steering wheel switch
Continuity
Connector Terminal Connector Terminal
E90 2 M52 2 Existed
Heated steering wheel relay GroundContinuity
Connector Terminal
E90 2 Not existed
Fuse block (J/B) Heated steering wheel switch Continuity
Connector Terminal Connector Terminal
M1 2A M52 1 Existed
Fuse block (J/B) GroundContinuity
Connector Terminal
M1 2A Not existed
Revision: 2010 May2011 QX56

STC-1
STEERING
C
DE
F
H I
J
K L
M
SECTION STC
A
B
STC
N
O P
CONTENTS
STEERING CONTROL SYSTEM
PRECAUTION ................ ...............................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
2
SYSTEM DESCRIPTION ..............................4
COMPONENT PARTS ................................... .....4
Component Parts Location .................................. ......4
Component Description .............................................4
Power Steering Control Unit ......................................4
Power Steering Solenoid Valve .................................4
SYSTEM ..............................................................5
EPS SYSTEM ........................................ ......................5
EPS SYSTEM : System De scription .........................5
EPS SYSTEM : Fail-Safe ..........................................6
ECU DIAGNOSIS INFO RMATION ...............8
POWER STEERING CONTROL UNIT ........... .....8
Reference Value ................................................. ......8
Fail-Safe ....................................................................9
WIRING DIAGRAM ......................................10
ELECTRONICALLY CONTROLLED POWER
STEERING SYSTEM ...................................... ....
10
Wiring Diagram ................................................... ....10
BASIC INSPECTION ...................................13
DIAGNOSIS AND REPAIR WORK FLOW .......13
Work Flow ............................................................ ....13
DTC/CIRCUIT DIAGNOSIS .........................14
POWER SUPPLY AND GROUND CIRCUIT ....14
Diagnosis Procedure ........................................... ....14
POWER STEERING SOLENOID VALVE .........16
Component Function Check ....................................16
Diagnosis Procedure ...............................................16
Component Inspection .............................................17
ENGINE SPEED SIGNAL CIRCUIT ..................18
Diagnosis Procedure ........................................... ....18
VEHICLE SPEED SIGNAL CIRCUIT ................20
Diagnosis Procedure ...............................................20
SYMPTOM DIAGNOSIS ..............................22
UNBALANCE STEERING WHEEL TURNING
FORCE (TORQUE VARIATION) .......................
22
Description ........................................................... ....22
Diagnosis Procedure ...............................................22
REMOVAL AND INSTALLATION ...............23
POWER STEERING CONTROL UNIT ..............23
Removal and Installation ..................................... ....23
Revision: 2010 May2011 QX56

STC-10
< WIRING DIAGRAM >
ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM
WIRING DIAGRAM
ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM
Wiring Diagram INFOID:0000000006256123
JCGWM0392GB
Revision: 2010 May2011 QX56

ELECTRONICALLY CONTROLLED POWER STEERING SYSTEMSTC-11
< WIRING DIAGRAM >
C
DE
F
H I
J
K L
M A
B
STC
N
O P
JCGWM0393GB
Revision: 2010 May2011 QX56

STC-12
< WIRING DIAGRAM >
ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM
JCGWM0394GB
Revision: 2010 May2011 QX56

STC-14
< DTC/CIRCUIT DIAGNOSIS >
POWER SUPPLY AND GROUND CIRCUIT
DTC/CIRCUIT DIAGNOSIS
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000006256125
1.CHECK POWER SUPPLY (1)
1. Turn the ignition switch OFF.
2. Disconnect power steering control unit harness connector.
3. Check the voltage between power steering control unit harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start the engine.
5. Check the voltage between power steering control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK POWER SUPPLY (2)
1. Turn the ignition switch OFF.
2. Check 10A fuse (#3).
3. Disconnect fuse block (J/B) harness connector.
4. Check the continuity between power steering cont rol unit harness connector and fuse block (J/B) harness
connector.
5. Check the continuity between power st eering control unit harness connector and ground.
Is the inspection result normal?
YES >> Perform trouble diagnosis for ignition power supply circuit. Refer to PG-89, "Wiring Diagram -
IGNITION POWER SUPPLY -".
NO >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn the ignition switch OFF.
2. Check the continuity between power st eering control unit harness connector and ground.
Power steering control unit
—Voltage
Connector Terminal
M108 3 Ground 0 V
Power steering control unit — Voltage
Connector Terminal
M108 3 Ground Battery voltage
Power steering control unit Fuse block (J/B) Continuity
Connector Terminal Connector Terminal
M108 3 M1 2A Existed
Power steering control unit —Continuity
Connector Terminal
M108 3 Ground Not existed
Revision: 2010 May2011 QX56